Abrasive implement



Sept... 19, 1944. R s, MANCHESTER 2,358,724

ABR'AsIvE IMPLEMENT Filed Aug. 14, 1942 2 sheets-'sheet 1 Sept.l 19, 1944. R. s. MANCHESTER 2,158,124

ABRAS IVE IMPLEMENT Filed Aug. 14,1942 2 sheets-sheet 2 1%@ '1v1/fyi 1 20 4 of the strip in successive convolutions imparts to the bob as a whole, the desired tapered, conical, convexly rounded shape, as indicated in Figures 1, 2, 3, 6, and 8.

Practically any desired shape of bob can be produced, by appropriately designing the blank before it is wound on the mandrel. If a relative- 1y blunt bob is desired, the angle between edges I9 and i8 should be decreased, as indicated in Figure 9, whereas if a more pointed, sharply tapered bob is to be produced, the angle' should be increased, as indicated in Figure 4. Figures 6 and 'I illustrate an intermediate shape.

. As stated above, the adhesive i1 may be ap- I plied in the form of a strip along the base edge After the bob has been produced, it may be used on a spindle having a smooth reduced end 26, an intermediate threaded section 21 and an abutment shoulder 28. The threads 21 may readily be screwed into the paper or cloth constituting the Wall of the hollow bore 29 of the implements, to secure the same upon the spindle. The threads 21 project outwardly slightly beyond the diameter of the smooth end 26, the latter being of the same size as the winding mandrel and thel bore of the implement. Any similar spindle or rotatable support may be used, such as one provided with fiutes, a taper, or the like.

As shown in Figures 10 and l1, a bob in accordance with the present invention may be produced from a strip 30 having parallel side edges. In this case, the strip is wound on the mandrel so that successive convolutions are moved axially, progressively as the roll is built up. As a result, one end 3| of the implement is convexly rounded and the other 32 has a similar concavity formed therein. A bob of this type may be mounted upon a spindle 33 provided with a rigid supporting heador plug 34 adapted to support the hollow base end of the bob and to which the latter may be secured by adhesive, if desired. 0n the other hand, the rear end may be left unsupported, if a flexible skirt at that end is desired. l

As indicated .in Figure 1, the strip of coate abrasive materal is wound up with the abrasive surface facing outwardly in all of theconvolutions and with the backing facing inwardly. The

f backing preferably is cloth, although any other materials, such as paper and the\like. may be employed.

The exposed surfaces of the coated abrasive, although actually disposed on substantially concentric cylindrical or spiral surfaces. present a tapering, conical, or convexly rounded abrasive surface to the implement as a whole because of their progressively stepped relation, veach to the other. Hence, in use, the article functions in.

the same manner asa molded or' dipped abrasive bob.

Moreover, as successive layers of the coated abrasive are worn away, completely fresh layers face's function with the same efficiency as the original surfaces. In this connection, it is important to note that, at the working end-of the implement, the spaces between the grains in successive layers are not filled with adhesive, as is the case at the base end. Hence, the. cutting efficiency of the layers is not impaired by the presence of adhesive employed to secure the convolutions to each other.

It is thought that, from the foregoing description, the nature and advantages of the present invention will be entirely clear to those skilled in the art. It must be understood that the invention is not limited to the details of construction, described above and shown in the accompanying drawing, but covers all modifications coming within the scope of the appended claims and their equivalents.

Iclaim:

1. An abrasive implement having a base and a tapered forward working end, comprising a coated abrasive strip wound upon itself in a plurality of contacting convolutions with the abrasive surface disposed outwardly, the edge of the strip in successive convolutions adjacent the forward end7 being stepped back from the correspending edge of the convolutions therebelow and exposing the abrasive surface thereof and thereby imparting a convex tapered shape to the forward working end of the implement as a whole, the successive convolutions adjacent said forward working end being unsecured to each other, thereby providing a substantially yielding and resilient working end.

2. An abrasive implement having a base and a tapered forward working end, comprising a plurality of mutually contacting convolutions of coated abrasive wound with the abrasive surface outwardly and with an edge of successive convolutions adjacent the forward end positioned to expose the abrasive surface of the convolutions therebelow, thereby providing a, generally tapered or conical abrasive surface at the forward working.l end of the implement, the contacting convolutions adjacent the forward end being unsecured to each other, thereby providing a yielding and resilient abrasive surface. Y

w3. An abrasive implement comprising a P1u rality of contacting convolutions of coated abrasive adhesively secured together adjacent theA base end of the implement onlyand wound with an edge of successive convolutions positioned remote from the baseend to expose afmarginal portion of the abrasive surface of the convolutions therebelow, thereby providing a' yielding, resilient, generally convex abrasive surface at the working end of the implement.

4. An abrasive implement having a base and a working face at the opposite end, comprising a coated abrasive strip wound upon itself in 4a. plurality of contacting convolutions with the abrasive surface disposed outwardly, the axially outermost edge of the convolutions being Progresare exposed forsubsequent use. These fresh sursively stepped hack toward the base end to provide a convexly rounded working end face for the implement as a whole, the successive convo-- lutions adjacent the working end being unsecured to each other, thereby providing a relativelyyielding and resilient working end face.

5. An abrasive implement having a base end and a working face at the opposite end comprising a coated abrasive strip wound upon itself in a plurality of contacting convolutions with the abrasive surface disposed outwardly, the axially outermost edge of successively wound convolutions being progressively stepped back to provide a tapered abrasive working end for the implement as a whole, the successive convolutions being adhesively secured to each other adjacent the base end only, leaving the convolutions in the working end unsecured, thereby providing a relaitvely rigid base and a relatively yielding and resilient working end.

6. An abrasive bob having a base and a working end, comprising a tapered, coated abrasive strip wound upon itself in a. plurality of contacting convolutions adhesively secured together with one edge of successive convolutions lying in a. single transaxlal plane at the base of the bob and the other edge stepped back progres-- siveiy and exposing the abrasive surface of the successively wound convolutions and providing a generally convex, tapered working end for the bob as a whole, the spaces betweenthe grains in successive layers adjacent the working end of the bob being relatively free from adhesive such as would impair the abrasive eillciency of said working end.

7. An abrasive bob having a base at one end and a working face at4 the other, comprising a tapered, coated abrasive strip wound upon itself in a plurality of contacting convolutions with one edge of successive convolutions lying in a single transaxial plane at the base of the bob. and a layer of adhesive adjacent said one edge only of the strip securing the successivev convdlutions together. the other edge of the strip being stepped back progressively from the innermost to the outermost convolution, and exposing the abrasive surface of each inner convolution axially therebeyond, and providing a generally tapered abrasive working end face for the bob as a whole.

8. A bob in accordance with claim 6 characterized in that the convolutions adjacent the first mentioned edge of the strip are adhesively united to each other and in that the convolutions r at the opposite end of the bob are in contact with each other but are unsecured, thereby providing a flexible working end face.

9. An abrasive implement having abaseend and a working end comprising a strip of coated abrasive cloth wound spirally in a plurality of contacting convolutions with one edge progressively and spirally receding from the working end of the roll toward the base end in successively wound convolutions 'and providing a generally tapered abrasive Vworking surface, the successive convolutions of abrasive cloth adjacent the working end being unse'cured to each other, thereby providing a relatively yielding and resilient abrasive surface.

10. An abrasive implement comprising a strip of coated abrasive cloth of substantially constantly increasing width from one end to the other. tightly wound spirally into a roll having and a working endcomprising a longitudinallyl tapered strip of coated abrasive cloth tightly wound in a roll having successive convolutions in contact and with the abrasive surface facing outwardly and with the wide end of the strip adjacent the center of the roll, the edge of the strip in successive convolutions at the base end of the implement being disposed in a single plane and being adhesively secured together, and the other edge receding in successively wound convolutions from the opposite end of the implement to provide a tapered abrasive working surface, the successive convolutions of abrasive cloth adjacent the last mentioned edge being unsecured to each other, thereby providing a relativelyyielding and resilient working surface.

l2. An abrasive implement having a base and a tapered forward working end. comprising a. coated abrasive strip wound upon itself about a longitudinal axis in a plurality of spiral, contacting convolutions with the abrasive surface disposed outwardly, said tapered forward working end having a surface such that all axial planes through the implement intersect the surface on parallel lines spaced progressively outwardly from the axis a distance substantially equal to the thickness of the coated abrasive strip, the contacting convolutions being adhesively secured to each other adjacent the base end only, leaving the convolutions unsecured at the forward end, to provide a relatively yielding and resilient abra sive surface.

RANDALL s. MANCHESTER.

'Patent No. 2,558,721.

CERHFICATE oF CQRRECTION.

September 19, 19h11..

RANDALL'S. MANCHESTER.

Itis hereby-certified that error appers in the printed specification of the above numbered patent requiring correction as follows: Page 2, second column, line 52, claim 5, before the word "remote" strike out "positioned" and insert the same-after "end" in 1ie'55, same claim; 1ne-58, claim l1., after "base" insert --end-f-f; and that the said Letters Patent should be read with this correction thereinthat the'same may conform to vthe record of the case in the Patent Office. I

signed and sealed this 5th day of Deeember, A. 1;. 19ML.-

` Leslie Frazer' (Seal) Ac'ting Commissioner vof. Patents.- 

